Big data refers to collections of large datasets difficult to handle with traditional database management tools and data processing applications. In recent years, big data analysis has been utilized to discover business trends and the like.
As a result of its large size, big data cannot be managed with existing database systems. Accordingly, when handling such data in database systems, there may be occasions where the data collected most recently is stored in database tables, and data from before that is moved to archive files for storage. As archive files are not usually accessible via the access methods provided by database systems, such an operation makes it difficult to perform analysis or other operations that make use of the data recorded in the archive file.
In order to solve such a problem, technologies are considered for making archives accessible as a part of the database itself. For example, Patent Document 1 discloses a system that extracts data that matches a predetermined extraction condition from a database, moves the data to an archive file, and stores date information for the moved data in a dictionary. In this system, in response to receiving a data search request specifying a date, in addition to performing data retrieval from the database, it is possible to read out an archive file containing data for the specified date and perform data retrieval by referring to the dictionary.